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Homework Help: Linear Algebra Question

  1. Mar 14, 2010 #1
    The solution of the system

    ax + ay - z = 1
    x - ay - az = -1
    ax - y + az = 1

    is (x,y,z) = (a,b,a). If a is not an integer, what is the numberical value of a + b.

    So I guess i should plug in (a,b,a) for (x,y,z) first..

    a^2 + ab - a = 1
    a - ab + a^2 = -1
    a^2 - b - a^2 = 1

    I am not sure how to solve for a + b though and I am not sure how part that a is not an integer comes into play can someone help?
  2. jcsd
  3. Mar 14, 2010 #2
  4. Mar 14, 2010 #3


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    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi jcharky ! Welcome to PF! :smile:

    (try using the X2 tag just above the Reply box :wink:)

    Your second and third equations have a2 the wrong way round. :redface:
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